In recent years, resin compositions curable by irradiation of activating rays such as ultraviolet rays have been used in various fields as adhesives, coating agents, and the like. A resin composition containing a polyene compound and a polythiol compound as its components has been known as one of the photo-curable resin compositions of this type (see Patent Document 1 to Patent Document 5).
The resin composition containing a polyene and a polythiol as its components has excellent transparency in a visible light region (400 to 800 nm), adhesive properties, and curing properties at the surface thereof in the air (hereinafter referred to as “surface curing properties”). Therefore, the resin composition has been used in various fields of optical components, electronic components, and the like as an adhesive for glass, transparent plastics, or the like.
In the recent opto-electronics field, the demand for adhesives having higher adhesive properties has increased with equipment performance improvement. A composition mainly including an acrylic raw material has been generally known as a photo-curable composition having high adhesive strength. Such an acrylic photo-curable resin composition has been known to suffer curing inhibition by oxygen in the air. The composition has thus required consideration, for example, performing nitrogen substitution for curing, or quickly curing the composition by exposure to light with high illuminance, in order to cure the surface thereof favorably. In addition, acrylic adhesives do not have strong adhesive properties to foil (adherend) of a metal such as copper or nickel that is used for a printed board or an electric member in which the metal foil is formed on a substrate such as glass and translucent resin. It has thus been difficult to apply the acrylic adhesives to the field of substrates and electric members.
A curable composition containing a polyene and a polythiol as raw materials has been developed as a photo-curable composition having higher adhesive strength (see Patent Document 6).
A triene and thiol-based cured product using an isocyanuric acid-based triene compound is disclosed for the purpose of improving heat resistance (see Patent Documents 7 and 8). Examples of the triene compound in the cured product include allyl alcohol derivatives, and triallyl isocyanurate is used particularly in view of reactivity with a compound having a mercapto group.
A composition in which a curable composition containing a polyene and a polythiol as raw materials is blended with various kinds of additives has been developed in order to increase the adhesive force (see Patent Document 9).